When running a command in the terminal this appears at the end

[Frog]

I'm using 16 Pro and cinnamon desktop ....

I just tried to run ...... sudo apt update ...... and I got this at the end ......

E: The repository 'Index of /jakar/qt-heif/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
E: The repository 'Index of /mark-pcnetspec/conky-manager-pm9/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.

This is in regards to uninstalling ...... conky manager .....

sudo apt-get remove --purge conky-manager

but I have seen it at the end of other commands also in regards to "not having a Release file"

I don't want to reinstall conky

[Aravisian]

This will appear as a warning whenever you update apt, because there is no Release File for Zorin OS 16 in that repository, rendering that repository useless to you. (It looks like it has been abandoned since Trusty - Ubuntu 14.04)
You can open Software & Updates and the "Other software" tab, find that entry in the list, click on it to select it, then click the remove button. That will get rid of it and the warning.

Alternatively, you can run

sudo add-apt-repository --remove ppa:jakar/qt-heif

in terminal to get rid of it.

[Frog]

Thank you sir .... I'll go the terminal route ....